Board index » delphi » Indices and client data sets

Quote

I was surprised to find that when a client data set is connected to a
table, it does not create index definitions which are the same as the
table. Is there any way to get it to to this or must I specify it
manually with TClientDataSet's AddIndex method ?
 

Quote

You must create the indexes manually.
OK. Too bad their are not created automatically.

Quote

You don't normally need indexes
for the small number of records that CDS is intended to hold.
Huh ? Why in the world is CDS restricted to a small number of records ?

Quote

Huh ? Why in the world is CDS restricted to a small number of records ?
Indices are helpful in finding a record among any number of records.
Welcome to Client/Server development.

Quote

Hi Edward,

First of all I suggest you read a book of Eric Harmon
named Delphi Kylix Database development.
You can read also some articles of Cary Jensen about ClientDatasets

I have two strategies .
1-For Small(dimension) tables I retrieve all the records and create the
indexes.

Quote

2-For Big Tables(Facts) I retrieve just some records based on parameters
typed by the users.(Like Bill Said).

I define the indexes (for the dimension tables)Manually and at design
time.
I think It won´t be difficult for you to define these indexes at run
time,since you can retrieve the metadata indexes information(At least I

Quote

Since indexes are utilized by the RDBMS, what would retrieving metadata

Quote

I agree with you that Delphi should be smarter at design time.
What does Delphi not do that would make it "smarter"?

Quote

"Marcello Dias" <XXXX@XXXXX.COM>writes
news:4294ddd6$XXXX@XXXXX.COM...
Just curious, assuming the data is coming from a RDBMS, what creating local
indexes do?

They let the user order the Dbgrid by the column he wants for example.

Quote

>2-For Big Tables(Facts) I retrieve just some records based on parameters
typed by the users.(Like Bill Said).
>

Since indexes are utilized by the RDBMS, what would retrieving metadata
indexes do for the client?
The guy asked that he wants to create indexes at the client side that match the ones he has at the server side,since Delphi don´t do it automatically.I think this is the only way.

Quote

.

What does Delphi not do that would make it "smarter"?
Show a list of the RDBMS Indexes at Design Time.

Quote

Quote

>Just curious, assuming the data is coming from a RDBMS, what creating
local
>indexes do?
>
They let the user order the Dbgrid by the column he wants for example.

Yes, good point (I've done that myself).

Quote

>Since indexes are utilized by the RDBMS, what would retrieving metadata
>indexes do for the client?
The guy asked that he wants to create indexes at the client side that
match the ones he has at the server side,since Delphi don´t do it

Quote

>What does Delphi not do that would make it "smarter"?
Show a list of the RDBMS Indexes at Design Time.
Why would that make Delphi "smarter"? (Putting my DBA hat on) If one of our

Quote

"Marcello Dias" <XXXX@XXXXX.COM>writes
client.
Indexes are designed for server performance, not for the developer to use in
his/her code.

>>What does Delphi not do that would make it "smarter"?
>Show a list of the RDBMS Indexes at Design Time.

Why would that make Delphi "smarter"? (Putting my DBA hat on) If one of our
developers is somehow using (and relying on) the RDBMS indexes in their
code, he/she will not touch my database (taking hat off). I am pleased that
Delphi is smart enough by not letting a developer do that at design time.
Hi Kevin,